libcxxabi/test/test_aux_runtime.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // UNSUPPORTED: no-exceptions
  10
  11 #include <typeinfo>
  12
  13 //  Test taken from 5.2.8.2
  14 //  When typeid is applied to a glvalue expression whose type is a polymorphic
  15 //  class type, (10.3), the result refers to a std::type_info object
  16 //  representing the type of the most derived object (1.8) (that is, the
  17 //  dynamic type) to which the glvalue refers. If the glvalue expression is
  18 //  obtained by applying the unary * operator to a pointer(68) and the pointer
  19 //  is a null pointer value (4.10), the typeid expression throws the
  20 //  std::bad_typeid exception (18.7.3).
  21 //
  22 //  68) If p is an expression of pointer type, then *p, (*p), *(p),
  23 //      ((*p)), *((p)), and so on all meet this requirement.
  24 bool bad_typeid_test () {
  25     class A { virtual void f() {}};
  26     class B { virtual void g() {}};
  27
  28     B *bp = NULL;
  29     try {bool b = typeid(*bp) == typeid (A); ((void)b); }
  30     catch ( const std::bad_typeid &) { return true; }
  31     return false;
  32 }
  33
  34
  35 //  The value of a failed cast to pointer type is the null pointer value of
  36 //  the required result type. A failed cast to reference type throws
  37 //  std::bad_cast (18.7.2).
  38 bool bad_cast_test () {
  39     class A { virtual void f() {}};
  40     class B { virtual void g() {}};
  41     class D : public virtual A, private B {};
  42
  43     D d;
  44     B *bp = (B*)&d;     // cast needed to break protection
  45     try { D &dr = dynamic_cast<D&> (*bp); ((void)dr); }
  46     catch ( const std::bad_cast & ) { return true; }
  47     return false;
  48 }
  49
  50 int main ( ) {
  51     int ret_val = 0;
  52
  53     if ( !bad_typeid_test ()) {
  54         ret_val = 1;
  55     }
  56
  57     if ( !bad_cast_test ()) {
  58         ret_val = 2;
  59     }
  60
  61     return ret_val;
  62 }